Biology
This organelle contains DNA and controls the activities of the cell.
nucleus
This family of elements contains the most reactive non-metals.
the halogens
The angle between the incident ray and the normal is called this.
angle of incidence
Scientists use these annual growth patterns in trees to study past climates.
tree rings
Gas exchange occurs across the walls of these microscopic structures in the lungs.
alveoli
A tissue is best defined as this.
a group of similar cells working together to perform a specific function
An atom has 17 protons and 18 electrons. What is its charge?
-1
This type of lens causes parallel light rays to converge.
convex lens
Tree rings, ice cores, and sediment records are examples of this type of climate evidence.
proxy records (proxy data)
During an acid-base neutralization reaction, these two products are formed.
water and a salt
Explain why root hair cells are effective at absorbing water and minerals.
because they have a large surface area
Determine the formula of the compound formed between calcium and nitrogen.
Ca₃N₂
Explain why a straw appears bent when placed in water.
because light refracts as it moves between air and water
This greenhouse gas has a much greater warming effect per molecule than carbon dioxide and is commonly released by livestock.
methane (CH₄)
A solution changes blue litmus paper red and has a pH of 2. Identify two pieces of evidence that indicate it is acidic.
a pH below 7 and turning blue litmus red
This plant tissue is responsible for transporting sugars throughout the plant.
phloem
Balance the equation:
Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
A concave mirror can produce both real and virtual images because of this factor.
the object's position relative to the focal point
This greenhouse gas is released from fertilizers and agricultural soils.
nitrous oxide (N₂O)
An image formed by a convex lens is inverted and can be projected onto a screen. This type of image is called what?
real image
A heart muscle cell contains many mitochondria. Explain why.
because it requires large amounts of ATP for continuous contractions
Predict the products of:
AgNO₃ + NaCl → ?
An object is placed inside the focal length of a convex lens. Describe the image.
virtual, upright, and enlarged
Explain why scientists use proxy data when studying climates from thousands of years ago.
because direct temperature measurements were not available in the distant past
Stem cells are unique because they can perform this function.
differentiate into specialized cell types